Bristol > Edinburgh > Durham = Warwick (In my opinion)
Bristols a great City, loads of places with a lot of diversity, something for everyone. Edinburgh has a decent night-life, but its incredibly costly in some places, and generally I don't feel it has as much as Bristol in what it offers. Durham is a effectively a town, even though its a City and you're more likely to find pubs and some bars rather than the big clubs you'd find in the large cities - Having said that a family friend goes there and loves it. Warwick is on a campus which is quite a way from Warwick itself, but reasonably close to Coventry, which in all honesty is a bit of a ****hole but I can't really comment on it as I don't know much about it, but from other people I've got the impression that its a pretty remote university meaning that the night-life lacks a bit.